In the diagram above, each of fifteen private colleges is represented by a dot and an X on a vertical line. The X indicates the college’s annual income from tuition in 2008. The dot, above or below on the same dashed vertical line, indicates the college’s annual income in 2008 from investments such as endowments. The base of the vertical dashed line indicates the number of students at that college in 2008.

For how many colleges shown is the investment income in 2008 more than double the same college’s tuition income in 2008?

A. none
B. one
C. two
D. three
E. four

Colleges' investment incomes are the dots, and the tuition incomes are the X’s. For how many colleges is the dot twice as high as the X? Well, for the far left college, that dot is very high, and the X is relatively low, so that dot is definitely more than twice as high as that X. Take a look at the next—dot at around $460M and X at around $250M, so the dot falls short of twice as high as the X, so this one doesn't count. Take a look at the next—dot at around $520M and X at around $260M, so arguably, the dot is almost exactly twice as high as the X, but not more than twice as high, so this one doesn't count either. Then for the next few schools, the X’s are considerably higher, more than half the height of the dots, and after, the remaining schools have X’s higher than the dots—none of these can possibly count. Therefore, the only college to satisfy this condition is the one on the far left.

Answer = (B).